This invention relates to folding knives having locking means automatically movable to prevent movement of one or more blades away from the fully open position until the lock is manually released and, more particularly, to a novel and uniquely configured spring element and placement thereof within such a knife assembly.
Reference is made to U.S. Pat. No. 4,805,303 of the present inventor entitled "Folding Knife with Lock Open Feature" having an issue date of Feb. 21, 1989. The knife assembly described therein incorporates a beam spring associated with a lock lever and blade for urging the lock lever to engage a notch in the blade tang to keep the blade from moving in a direction away from the fully open position. Manual pressure exerted upon the exposed, opposite end of the lock lever releases the blade to allow it to fold into a space within the handle in the manner shown and described. The beam springs are positioned directly beneath and in the same plane of their associated lock levers within the knife assembly which dictates that the overall housing dimensions of the knife defined by the outer cover pieces and bolsters, be significantly larger than the dimensions of the blades which are foldable therein.
When the blades of the knife construction of the aforementioned patent are moved into their folded or closed position, the edge of their blade tangs come into contact with the lock levers to stop further rotation of the blades and therefore prevent contact of the sharpened edges of the blades with the beam springs. However, manual pressure exerted upon the folded blade, which occurs when grasping the knife housing in the intended manner for using an unfolded blade, causes the folded blade to pivot further and "bottom out" against its associated beam spring resulting in dulling of the sharpened edge.
It is a principal object of the present invention to provide a folding knife having a lock open feature in which the outer perimeter length and height dimensions of the knife housing closely approximate the corresponding length and height dimensions of the blades or other such implements foldable therein.
It is a further object of the present invention to provide a folding knife having a lock open feature which will not permit the sharpened edges of the blades to contact any element contained within the housing of the knife assembly when the blades are in their folded or closed position.
It is another object of the present invention to provide a folding knife having a lock open feature in which the position and configuration of the beam spring used to urge the locking mechanism into engagement with the notch in an associated blade tang permits the size of the blades to approximate more closely the size of the knife handle.
A still further object is to provide a novel beam spring construction for incorporation in an improved folding knife assembly wherein one or more of such beam springs may be appropriately positioned and configured for employment in knives having only one blade or a plurality of blades pivoted either at the same or at opposite ends of the handle.
Other objects will in part be obvious and in part appear hereinafter.